The compensating centers which were associated with N in N-doped material were investigated. A local vibrational mode of N was observed in N-doped samples which had been grown by molecular beam epitaxy. This N absorption band indicated that most of the doped N atoms substituted at Se sites and formed Zn-N bonds which had tetrahedral symmetry. Ion-beam analyses were performed on N-implanted and N2-implanted specimens in order to obtain some insight into the location of N2 in the lattice. It was found that the N atoms were located at substitutional sites, while the N2 in N2-implanted material was located at random sites. It was suggested that there was no evidence for the existence of N2 sites in molecular beam epitaxially grown samples.

C.D.Song, Y.H.Wu, M.Suezawa, F.Nishiyama, H.Katayama-Yoshida, T.Yao: Materials Science Forum, 1995, 196-201, 297-302